08. Can aliens breathe without oxygen helmets? (A K2S Question)

From The Space Library

Can fish breathe under water? Of course they can. It is highly likely that any aliens we encounter will breathe some type of atmosphere. But they might not breathe the same atmosphere as we breathe. It could be oxygen or maybe nitrogen or some other gas. It is interesting to note that the first organisms to live on Earth did not breathe oxygen. Instead they were breathing methane gas, a gas that is poisonous for us. The Earth's atmosphere changed to oxygen, a gas that was poisonous for these early Earth creatures but is safe for us.

---

Answer provided by Robby Gaines

Question and Answer extracted from the book Kids to Space - by Lonnie Schorer

Buy This Book Click here